The present invention relates in general to methods and apparatus for forming conformable garments such as diapers having selected discrete elasticized areas on a high speed production basis; and, more particularly to an improved heat roll for heat treating selected spaced areas of stretched thermoplastic elastomeric material so as to "kill" the elastic properties of the heat treated zones.
The general arrangement for "heat-killing" selected areas of elastomeric ribbons employing a driven roll having a peripheral surface defining alternate heated zones and relatively cool zones is disclosed in the above-mentioned copending application Ser. No. 94,421. As disclosed therein, the heated roll is provided with a pair of opposed arcuate grooves which receive arcuate insulating strips defining the non-heated zones and a chill roll is disposed to make contact with the entire circumferential surface of the heated roll. While this arrangement has been generally satisfactory under initial start-up conditions and at moderate production speeds, the heat in the "heat-kill" roll still tends to migrate from the heated to the non-heated zones, and the chill roll tends to cool the heated as well as the non-heated zones on the heated roll.
Accordingly, it is the primary aim of the present invention to provide a "heat-kill" roll wherein the non-heated zones are more effectively isolated from the heated zones and only the non-heated zones are cooled by engagement with one or more chill rolls.
It is a more particular object of the invention to provide such a "heat-kill" roll wherein the non-heated zones along substantially their entire arcuate length are separated from the heated zones by an insulating air space.
A further object is to locate the non-heated zones at a slightly greater radial distance from the roll axis than the heated zones so that only the non-heated zones engage a companion chill roll.